Readily available chemical added to your gas tank in small proportion improves the fuel's ability to vaporize completely by reducing the surface tension that inhibits vaporization of some fuel droplets. This common inexpensive chemical can be purchased in most hardware stores and may increase your mileage by as much as 12% to 18%. This is just another secret that the big oil companies have kept to themselves so get this information now while this chemical is still available. Full report.